D.C. Mayor Vincent C. Gray is vowing to make the District the nation’s “healthiest, greenest and most livable” city within 20 years and is launching dozens of initiatives to curb energy use, reduce traffic and boost access to fresh fruits and vegetables.

If fully implemented, new buildings would be required to generate at least as much energy as they consume, driving would be dramatically reduced and the District government offices would get much of their power from nearby wind farms.

Residents would be encouraged to grow their own produce and start food co-ops, and the city would operate several public orchards.

Although cars would still dominate city streets, it would cost more to park them and they would be expected to share the road with a streetcar system and tens of thousands of bicyclists. By 2032, according to the plan, a quarter of all commuter trips would be by bike or foot, and half would be by public transportation.

“Not every proposal will work out just as envisioned. Some details will be refined over time, and some actions may fail, but with this implementation plan, we will move forward with clear goals in sight,” said Gray, who will officially announce the plan Wednesday morning along the Anacostia River near Nationals Park.

But the proposals will cost hundreds of millions of dollars and could be met with skepticism from some residents.

“Black folks are concerned about the environment, but they are also concerned about jobs,” said D.C. Council member Marion Barry (D-Ward 8). “Gardens on roofs are fine, but if you are hungry, it’s not enough. You might have clean air to breathe, but it doesn’t matter if you are also broke.”

In all, Gray has identified more than 100 policies either he or a future mayor should pursue to reduce greenhouse-gas emissions and energy use by 50 percent by 2032. The plans also identify strategies for housing an additional 250,000 residents by 2032 in an environmentally sensitive way.

Some of the changes could begin within months; some are underway.

Gray has said that over the next year, he’ll spend $4.5 million to create 10 “mini” neighborhood parks out of existing parking spaces, create community gardens in all eight city wards and examine each city-owned building to determine if they can be retrofitted with green or solar roofs, according to the 129-page plan. The plan also includes new short-term goals to establish a facility to accept compostable materials and use sewage byproducts in city plantings.

A second phase of the program, which would be launched within five years, calls for planting 8,600 trees annually, aggressively enforcing a ban on “idling vehicle engines” and raising rates at parking meters in some commercial areas where space is limited.

Gray also is considering a citywide ban on disposable foam containers used for food and beverages, a proposal similar to one made last week by New York Mayor Michael R. Bloomberg (I). Other “medium term” goals include having 500 charging stations for electric vehicles, an additional 200 Capital Bikeshare stations, twice as many bike lanes and 2 million additional square feet of green roofs within 10 years.

Longer-term goals include a new pricing schedule in which residents would pay per can of garbage that the city hauls away. Also contemplated is renewing efforts to implement a bottle deposit system, which has been floated several times in recent decades. The city will also work to eliminate mold and other toxins from its public housing developments and to impose new requirements on utilities, mandating that at least 20 percent of the city’s electricity come from renewable sources.

Gray, who is up for reelection next year and says his plan would create thousands of jobs, hopes to make his sustainability push a hallmark of his administration.

He launched the initiative in 2011 by organizing a task force to study the issue. In April, Gray unveiled broad sustainability goals for 2032, including making the Anacostia and Potomac rivers swimmable and fishable. The D.C. Department of the Environment and the Office of Planning spent the past nine months developing the initiatives Gray will announce Wednesday.

Although some goals have been decried as far-fetched, administration officials say Gray has been adamant that they help guide his decisions. “We can become more economically strong, healthy and resilient by reducing our environmental footprint,” said Keith A. Anderson, acting director of the Department of the Environment. In December, Gray and the D.C. Council agreed to extend solar tax credits for homeowners, regulate the use of fertilizers near waterways and allow residents to maintain beehives.

Several of the new proposals, such as changing parking requirements and making it easier for homeowners to create apartments on their property, are already included in a zoning rewrite that the Zoning Commission is expected to vote on this year.

But the District is nearing its debt cap, so it’s unclear how it will finance some of the more expensive initiatives, including spending $500 million to make city buildings more energy efficient.

“I am committing the full resources of the District government to ensuring that we achieve the goals it sets out,” Gray said.

Mike DeBonis contributed to this report.

Tim Craig is The Post’s bureau chief in Pakistan. He has also covered conflicts in Iraq, Afghanistan and within the District of Columbia government.

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